The development and upgrade of test installations, instrumentation and the data acquisition system of an existing turbofan engine test rig are described for an experimental program which was planned and initiated to investigate the transient unsteady operation of gas turbine engines with an emphasis on compressor operation. The objective of the program was to examine aerodynamic instabilities s...

Cells of the bacterium Escherichia coli were tethered and spun in a high-frequency rotating electric field at a series of discrete field strengths. This was done first at low field strengths, then at field strengths generating speeds high enough to disrupt motor function, and finally at low field strengths. Comparison of the initial and final speed versus applied-torque plots yielded relative m...

A low-speed counter-rotating axial flow compressor (CRAC) with single circumferential grooved casing treatment (CT) was investigated numerically. Both steady and time-accurate numerical calculations were performed to study the effects of the single grooved CTs over the rear rotor on the stability enhancement and the unsteadiness of tip leakage flow (TLF) in the CRAC. Parametric studies indicate...

Axial flow compressors are required to operate over a wide range of mass flow rate and rotational speeds at high efficiency in industrial gas turbines. However, the useful range of operation of the axial compressor is limited by the onset of two instabilities known as surge and rotating stall. To resolve these problems, variable stator blades or VGVs are considered by optimising the blade setti...

This Nemorandum describes an investiga%ion into the flow fluctuations occurring in two mismatched otaiges in the N.G.T.E. 106 low speed CCmpre3s0r. It3 pur~~ose is to contribute tn a gener,ll understanding of surgin,-, and unstea:iy flow-phenomena in Pull scale compressors when operating in a mismatched condition. licit wire anemometers were used to ex:lmine the fluctuations, measurements being...